This is such a rare path it took me a while to figure out how to test
this after soring out the locking.
This patch does several things.
- The variables used are moved into a structure and declared in vt_kern.h
- A spinlock is added so we don't have SMP races updating the values.
- Instead of raw pid_t value a struct_pid is used to guard against
pid wrap around issues, if the daemon to spawn a new console dies.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As we stop storing pid_t's and move to storing struct pid *. We need a way to
get the pid_t from the struct pid to report to user space what we have stored.
Having a clean well defined way to do this is especially important as we move
to multiple pid spaces as may need to report a different value to the caller
depending on which pid space the caller is in.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently the signal functions all either take a task or a pid_t argument.
This patch implements variants that take a struct pid *. After all of the
users have been update it is my intention to remove the variants that take a
pid_t as using pid_t can be more work (an extra hash table lookup) and
difficult to get right in the presence of multiple pid namespaces.
There are two kinds of functions introduced in this patch. The are the
general use functions kill_pgrp and kill_pid which take a priv argument that
is ultimately used to create the appropriate siginfo information, Then there
are _kill_pgrp_info, kill_pgrp_info, kill_pid_info the internal implementation
helpers that take an explicit siginfo.
The distinction is made because filling out an explcit siginfo is tricky, and
will be even more tricky when pid namespaces are introduced.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
To avoid pid rollover confusion the kernel needs to work with struct pid *
instead of pid_t. Currently there is not an iterator that walks through all
of the tasks of a given pid type starting with a struct pid. This prevents us
replacing some pid_t instances with struct pid. So this patch adds
do_each_pid_task which walks through the set of task for a given pid type
starting with a struct pid.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the last round of cleaning up the pid hash table a more general struct pid
was introduced, that can be referenced counted.
With the more general struct pid most if not all places where we store a pid_t
we can now store a struct pid * and remove the need for a hash table lookup,
and avoid any possible problems with pid roll over.
Looking forward to the pid namespaces struct pid * gives us an absolute form a
pid so we can compare and use them without caring which pid namespace we are
in.
This patchset introduces the infrastructure needed to use struct pid instead
of pid_t, and then it goes on to convert two different kernel users that
currently store a pid_t value.
There are a lot more places to go but this is enough to get the basic idea.
Before we can merge a pid namespace patch all of the kernel pid_t users need
to be examined. Those that deal with user space processes need to be
converted to using a struct pid *. Those that deal with kernel processes need
to converted to using the kthread api. A rare few that only use their current
processes pid values get to be left alone.
This patch:
task_session returns the struct pid of a tasks session.
task_pgrp returns the struct pid of a tasks process group.
task_tgid returns the struct pid of a tasks thread group.
task_pid returns the struct pid of a tasks process id.
These can be used to avoid unnecessary hash table lookups, and to implement
safe pid comparisions in the face of a pid namespace.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently proc_pident_lookup gets the names and types from a table and then
has a huge switch statement to get the inode and file operations it needs.
That is silly and is becoming increasingly hard to maintain so I just put all
of the information in the table.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem: An opendir, readdir, closedir sequence can fail to report
process ids that are continually in use throughout the sequence of system
calls. For this race to trigger the process that proc_pid_readdir stops at
must exit before readdir is called again.
This can cause ps to fail to report processes, and it is in violation of
posix guarantees and normal application expectations with respect to
readdir.
Currently there is no way to work around this problem in user space short
of providing a gargantuan buffer to user space so the directory read all
happens in on system call.
This patch implements the normal directory semantics for proc, that
guarantee that a directory entry that is neither created nor destroyed
while reading the directory entry will be returned. For directory that are
either created or destroyed during the readdir you may or may not see them.
Furthermore you may seek to a directory offset you have previously seen.
These are the guarantee that ext[23] provides and that posix requires, and
more importantly that user space expects. Plus it is a simple semantic to
implement reliable service. It is just a matter of calling readdir a
second time if you are wondering if something new has show up.
These better semantics are implemented by scanning through the pids in
numerical order and by making the file offset a pid plus a fixed offset.
The pid scan happens on the pid bitmap, which when you look at it is
remarkably efficient for a brute force algorithm. Given that a typical
cache line is 64 bytes and thus covers space for 64*8 == 200 pids. There
are only 40 cache lines for the entire 32K pid space. A typical system
will have 100 pids or more so this is actually fewer cache lines we have to
look at to scan a linked list, and the worst case of having to scan the
entire pid bitmap is pretty reasonable.
If we need something more efficient we can go to a more efficient data
structure for indexing the pids, but for now what we have should be
sufficient.
In addition this takes no additional locks and is actually less code than
what we are doing now.
Also another very subtle bug in this area has been fixed. It is possible
to catch a task in the middle of de_thread where a thread is assuming the
thread of it's thread group leader. This patch carefully handles that case
so if we hit it we don't fail to return the pid, that is undergoing the
de_thread dance.
Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for
providing the first fix, pointing this out and working on it.
[oleg@tv-sign.ru: fix it]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When listing loaded modules during an oops or panic, also list each
module's Tainted flags if non-zero (P: Proprietary or F: Forced load only).
If a module is did not taint the kernel, it is just listed like
usbcore
but if it did taint the kernel, it is listed like
wizmodem(PF)
Example:
[ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[ 3260.121729] [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8
[ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0
[ 3260.121748] Oops: 0002 [1] SMP
[ 3260.121753] CPU 1
[ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp
[ 3260.121785] Pid: 5556, comm: bash Tainted: P 2.6.18-git10 #1
[Alternatively, I can look into listing tainted flags with 'lsmod',
but that won't help in oopsen/panics so much.]
[akpm@osdl.org: cleanup]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modules using the genpool allocator need to be able to destroy the data
structure when unloading.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
During tracking down a PAE compile failure, I found that config.h was being
included in a bunch of places in i386 code. It is no longer necessary, so
drop it.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A new member in the ever growing family of call_usermode* functions is
born. The new call_usermodehelper_pipe() function allows to pipe data to
the stdin of the called user mode progam and behaves otherwise like the
normal call_usermodehelp() (except that it always waits for the child to
finish)
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Split the big and hard to read do_pipe function into smaller pieces.
This creates new create_write_pipe/free_write_pipe/create_read_pipe
functions. These functions are made global so that they can be used by
other parts of the kernel.
The resulting code is more generic and easier to read and has cleaner error
handling and less gotos.
[akpm@osdl.org: cleanup]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a generic implementation of ioremap_page_range() in
lib/ioremap.c based on the i386 implementation. It differs from the
i386 version in the following ways:
* The PTE flags are passed as a pgprot_t argument and must be
determined up front by the arch-specific code. No additional
PTE flags are added.
* Uses set_pte_at() instead of set_pte()
[bunk@stusta.de: warning fix]
]dhowells@redhat.com: nommu build fix]
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-m32r@ml.linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some filesystems, instead of simply decrementing i_nlink, simply zero it
during an unlink operation. We need to catch these in addition to the
decrement operations.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is mostly included for parity with dec_nlink(), where we will have some
more hooks. This one should stay pretty darn straightforward for now.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.
We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.
So, add a little helper function to do the decrements. We'll tie into it in a
bit to note when i_nlink hits zero.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ChangeLog:
Feedbacks from Andrew Morton:
- define TS_COMM_LEN to 32
- change acct_stimexpd field of task_struct to be of
cputime_t, which is to be used to save the tsk->stime
of last timer interrupt update.
- a new Documentation/accounting/taskstats-struct.txt
to describe fields of taskstats struct.
Feedback from Balbir Singh:
- keep the stime of a task to be zero when both stime
and utime are zero as recoreded in task_struct.
Misc:
- convert accumulated RSS/VM from platform dependent
pages-ticks to MBytes-usecs in the kernel
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There were a few accounting data/macros that are used in CSA but are #ifdef'ed
inside CONFIG_BSD_PROCESS_ACCT. This patch is to change those ifdef's from
CONFIG_BSD_PROCESS_ACCT to CONFIG_TASK_XACCT. A few defines are moved from
kernel/acct.c and include/linux/acct.h to kernel/tsacct.c and
include/linux/tsacct_kern.h.
Signed-off-by: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add extended system accounting handling over taskstats interface. A
CONFIG_TASK_XACCT flag is created to enable the extended accounting code.
Signed-off-by: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add some basic accounting fields to the taskstats struct, add a new
kernel/tsacct.c to handle basic accounting data handling upon exit. A handle
is added to taskstats.c to invoke the basic accounting data handling.
Signed-off-by: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: "Michal Piotrowski" <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This work is initially done by Zach Brown to add support for vectored aio.
These are the core changes for AIO to support
IOCB_CMD_PREADV/IOCB_CMD_PWRITEV.
[akpm@osdl.org: huge build fix]
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch cleans up generic_file_*_read/write() interfaces. Christoph
Hellwig gave me the idea for this clean ups.
In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods. This allows us
to cleanup all variants of generic_file_* routines.
Final available interfaces:
generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler
__generic_file_aio_write_nolock() - internal worker routine
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch vectorizes aio_read() and aio_write() methods to prepare for
collapsing all aio & vectored operations into one interface - which is
aio_read()/aio_write().
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Michael Holzheu <HOLZHEU@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the patch the three previous ones have been leading up to.
It changes the behavior of ReiserFS from loading and caching all the bitmaps
as special, to treating the bitmaps like any other bit of metadata and just
letting the system-wide caches figure out what to hang on to.
Buffer heads are allocated on the fly, so there is no need to retain pointers
to all of them. The caching of the metadata occurs when the data is read and
updated, and is considered invalid and uncached until then.
I needed to remove the vs-4040 check for performing a duplicate operation on a
particular bit. The reason is that while the other sites for working with
bitmaps are allowed to schedule, is_reusable() is called from do_balance(),
which will panic if a schedule occurs in certain places.
The benefit of on-demand bitmaps clearly outweighs a sanity check that depends
on a compile-time option that is discouraged.
[akpm@osdl.org: warning fix]
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch moves the bitmap loading code from super.c to bitmap.c
The code is also restructured somewhat. The only difference between new
format bitmaps and old format bitmaps is where they are. That's a two liner
before loading the block to use the correct one. There's no need for an
entirely separate code path.
The load path is generally the same, with the pattern being to throw out a
bunch of requests and then wait for them, then cache the metadata from the
contents.
Again, like the previous patches, the purpose is to set up for later ones.
Update: There was a bug in the previously posted version of this that resulted
in corruption. The problem was that bitmap 0 on new format file systems must
be treated specially, and wasn't. A stupid bug with an easy fix.
This is hopefully the last fix for the disaster that is the reiserfs bitmap
patch set.
If a bitmap block was full, first_zero_hint would end up at zero since it
would never be changed from it's zeroed out value. This just sets it
beyond the end of the bitmap block. If any bits are freed, it will be
reset to a valid bit. When info->free_count = 0, then we already know it's
full.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is a check in is_reusable to determine if a particular block is a bitmap
block. It verifies this by going through the array of bitmap block buffer
heads and comparing the block number to each one.
Bitmap blocks are at defined locations on the disk in both old and current
formats. Simply checking against the known good values is enough.
This is a trivial optimization for a non-production codepath, but this is the
first in a series of patches that will ultimately remove the buffer heads from
that array.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following possible cleanups:
- make the following needlessly global function static:
- ntp_update_frequency()
- make the following needlessly global variables static:
- time_state
- time_offset
- time_constant
- time_reftime
- remove the following read-only global variable:
- time_precision
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove a few unused defines and remove obsolete information from comments.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts the kernel ntp model into a model which matches the nanokernel
reference implementations. The previous patches already increased the
resolution and precision of the computations, so that this conversion becomes
quite simple.
<linux@horizon.com> explains:
The original NTP kernel interface was defined in units of microseconds.
That's what Linux implements. As computers have gotten faster and can now
split microseconds easily, a new kernel interface using nanosecond units was
defined ("the nanokernel", confusing as that name is to OS hackers), and
there's an STA_NANO bit in the adjtimex() status field to tell the application
which units it's using.
The current ntpd supports both, but Linux loses some possible timing
resolution because of quantization effects, and the ntpd hackers would really
like to be able to drop the backwards compatibility code.
Ulrich Windl has been maintaining a patch set to do the conversion for years,
but it's hard to keep in sync.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts time_freq to a scaled nsec value and adds around 6bit of extra
resolution. This pushes the time_freq to its 32bit limits so the calculatons
have to be done with 64bit.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
time_tolerance isn't changed at all in the kernel, so simply remove it, this
simplifies the next patch, as it avoids a number of conversions.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This folds update_ntp_one_tick() into second_overflow() and adds time_adjust
to the tick length, this makes time_next_adjust unnecessary. This slightly
changes the adjtime() behaviour, instead of applying it to the next tick, it's
applied to the next second.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts time_offset into a scaled per tick value. This avoids now
completely the crude compensation in second_overflow().
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not
performance critical). ntp_update_frequency() calculates the base tick length
using tick_usec and adds a base adjustment, in case the frequency doesn't
divide evenly by HZ.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move all the NTP related code to ntp.c
[akpm@osdl.org: cleanups, build fix]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The lock annotation macros __acquires, __releases, __acquire, and __release
all currently throw away the lock expression passed as an argument. Now
that sparse can parse __context__ and __attribute__((context)) with a
context expression, pass the lock expression down to sparse as the context
expression. This requires a version of sparse from GIT commit
37475a6c1c3e66219e68d912d5eb833f4098fd72 or later.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update RTC framework so that drivers can constify their method tables, moving
them from ".data" to ".rodata". Then update the drivers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
BUG_ON() does this unlikely check itself, as bugs in Linux are unlikely
anyway :)
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the ability to register for a command per-channel in the
IPMI driver.
If your BMC supports multiple channels, incoming messages can be useful to
have the ability to register to receive commands on a specific channel
instead the current behaviour of all channels.
Signed-off-by: David Barksdale <amatus@ocgnet.org>
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ncp specific compat ioctls are clearly local to one file system, so the
code can better live there.
This version of the patch moves everything into the generic ioctl handler
and uses it for both 32 and 64 bit calls.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Prevent multiple inclusions of include/linux/sysrq.h using traditional
#ifndef..#endif.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@enix.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add bisync and monosync serial protocol support to the synclink_gt driver.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
One of idiomatic ways to duplicate a region of memory is
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return -ENOMEM;
memcpy(dst, src, len);
which is neat code except a programmer needs to write size twice. Which
sometimes leads to mistakes. If len passed to kmalloc is smaller that len
passed to memcpy, it's straight overwrite-beyond-end. If len passed to
memcpy is smaller than len passed to kmalloc, it's either a) legit
behaviour ;-), or b) cloned buffer will contain garbage in second half.
Slight trolling of commit lists shows several duplications bugs
done exactly because of diverged lenghts:
Linux:
[CRYPTO]: Fix memcpy/memset args.
[PATCH] memcpy/memset fixes
OpenBSD:
kerberosV/src/lib/asn1: der_copy.c:1.4
If programmer is given only one place to play with lengths, I believe, such
mistakes could be avoided.
With kmemdup, the snippet above will be rewritten as:
dst = kmemdup(src, len, GFP_KERNEL);
if (!dst)
return -ENOMEM;
This also leads to smaller code (kzalloc effect). Quick grep shows
200+ places where kmemdup() can be used.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add infrastructure to track "maximum allowable latency" for power saving
policies.
The reason for adding this infrastructure is that power management in the
idle loop needs to make a tradeoff between latency and power savings
(deeper power save modes have a longer latency to running code again). The
code that today makes this tradeoff just does a rather simple algorithm;
however this is not good enough: There are devices and use cases where a
lower latency is required than that the higher power saving states provide.
An example would be audio playback, but another example is the ipw2100
wireless driver that right now has a very direct and ugly acpi hook to
disable some higher power states randomly when it gets certain types of
error.
The proposed solution is to have an interface where drivers can
* announce the maximum latency (in microseconds) that they can deal with
* modify this latency
* give up their constraint
and a function where the code that decides on power saving strategy can
query the current global desired maximum.
This patch has a user of each side: on the consumer side, ACPI is patched
to use this, on the producer side the ipw2100 driver is patched.
A generic maximum latency is also registered of 2 timer ticks (more and you
lose accurate time tracking after all).
While the existing users of the patch are x86 specific, the infrastructure
is not. I'd like to ask the arch maintainers of other architectures if the
infrastructure is generic enough for their use (assuming the architecture
has such a tradeoff as concept at all), and the sound/multimedia driver
owners to look at the driver facing API to see if this is something they
can use.
[akpm@osdl.org: cleanups]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jesse.barnes@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch defines:
* a generic boolean-type, named 'bool'
* aliases to 0 and 1, named 'false' and 'true'
Removing colliding definitions of 'bool', 'false' and 'true'.
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This fixes two things
Firstly someone mistakenly used "errata" for the singular. This causes
Dave Woodhouse to emit diagnostics whenever the string is read, and so
should be fixed.
Secondly the AMD AGP tunnel has an erratum which causes hangs if you try
and do direct PCI to AGP transfers in some cases. We have a flag for
PCI/PCI failures but we need a different flag for this really as in this
case we don't want to stop PCI/PCI transfers using things like IOAT and the
new RAID offload work.
I'll post some updates to make proper use of the PCIAGP flag in the
media/video drivers to Mauro.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Don't just do nothing: it'll cause busywaits all over writeback and page
reclaim.
For now, take a fixed-length nap. Will improve when NFS starts waking up
throttled processes.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the Ext3 device ioctl compat stuff from fs/compat_ioctl.c to the Ext3
driver so that the Ext3 header file doesn't need to be included.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the ReiserFS device ioctl compat stuff from fs/compat_ioctl.c to the
ReiserFS driver so that the ReiserFS header file doesn't need to be included.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move common FS-specific ioctls from linux/ext2_fs.h to linux/fs.h as FS_IOC_*
and FS_IOC32_* and have the users of them use those as a base.
Also move the GETFLAGS/SETFLAGS flags to linux/fs.h as FS_*_FL macros, and then
have the other users use them as a base.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the loop device ioctl compat stuff from fs/compat_ioctl.c to the loop
driver so that the loop header file doesn't need to be included.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Dissociate the generic_writepages() function from the mpage stuff, moving its
declaration to linux/mm.h and actually emitting a full implementation into
mm/page-writeback.c.
The implementation is a partial duplicate of mpage_writepages() with all BIO
references removed.
It is used by NFS to do writeback.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Create a new header file, fs/internal.h, for common definitions local to the
sources in the fs/ directory.
Move extern definitions that should be in header files from fs/*.c to
fs/internal.h or other main header files where they span directories.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Remove the duplicate declaration of exit_io_context() from linux/sched.h.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move some functions out of the buffering code that aren't strictly buffering
specific. This is a precursor to being able to disable the block layer.
(*) Moved some stuff out of fs/buffer.c:
(*) The file sync and general sync stuff moved to fs/sync.c.
(*) The superblock sync stuff moved to fs/super.c.
(*) do_invalidatepage() moved to mm/truncate.c.
(*) try_to_release_page() moved to mm/filemap.c.
(*) Moved some related declarations between header files:
(*) declarations for do_invalidatepage() and try_to_release_page() moved
to linux/mm.h.
(*) __set_page_dirty_buffers() moved to linux/buffer_head.h.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.
Signed-off-by: Jens Axboe <axboe@suse.de>
CFQ implements this on its own now, but it's really block layer
knowledge. Tells a device queue to start dispatching requests to
the driver, taking care to unplug if needed. Also fixes the issue
where as/cfq will invoke a stopped queue, which we really don't
want.
Signed-off-by: Jens Axboe <axboe@suse.de>
None of the in-kernel primitives for handling "atomic" counting seem
to be a good fit. We need something that is essentially free for
incrementing/decrementing, while the read side may be more expensive
as we only ever need to do that when a device is removed from the
kernel.
Use a per-cpu variable for maintaining a per-cpu ioc count and define
a reading mechanism that just sums up the values.
Signed-off-by: Jens Axboe <axboe@suse.de>
cfq_exit_lock is protecting two things now:
- The per-ioc rbtree of cfq_io_contexts
- The per-cfqd linked list of cfq_io_contexts
The per-cfqd linked list can be protected by the queue lock, as it is (by
definition) per cfqd as the queue lock is.
The per-ioc rbtree is mainly used and updated by the process itself only.
The only outside use is the io priority changing. If we move the
priority changing to not browsing the rbtree, we can remove any locking
from the rbtree updates and lookup completely. Let the sys_ioprio syscall
just mark processes as having the iopriority changed and lazily update
the private cfq io contexts the next time io is queued, and we can
remove this locking as well.
Signed-off-by: Jens Axboe <axboe@suse.de>
Move some members around and unionize completion_data and rb_node since
they cannot ever be used at the same time.
Signed-off-by: Jens Axboe <axboe@suse.de>
After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.
So kill/clean the remaining users, straight forward.
Signed-off-by: Jens Axboe <axboe@suse.de>
It is always identical to &q->rq, and we only use it for detecting
whether this request came out of our mempool or not. So replace it
with an additional ->flags bit flag.
Signed-off-by: Jens Axboe <axboe@suse.de>
As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The rbtree sort/lookup/reposition logic is mostly duplicated in
cfq/deadline/as, so move it to the elevator core. The io schedulers
still provide the actual rb root, as we don't want to impose any sort
of specific handling on the schedulers.
Introduce the helpers and rb_node in struct request to help migrate the
IO schedulers.
Signed-off-by: Jens Axboe <axboe@suse.de>
Right now, every IO scheduler implements its own backmerging (except for
noop, which does no merging). That results in duplicated code for
essentially the same operation, which is never a good thing. This patch
moves the backmerging out of the io schedulers and into the elevator
core. We save 1.6kb of text and as a bonus get backmerging for noop as
well. Win-win!
Signed-off-by: Jens Axboe <axboe@suse.de>
Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: Jens Axboe <axboe@suse.de>
* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (180 commits)
V4L/DVB (4641): Trivial: use lowercase letters in hex subsystem ids
V4L/DVB (4639): Cx88: add autodetection for alternate revision of Leadtek PVR
V4L/DVB (4638): Basic DVB-T and analog TV support for the HVR1300.
V4L/DVB (4637): Add a default method for VIDIOC_G_PARM
V4L/DVB (4635): Extend bttv and saa7134 to check for both AGP and PCI PCI failure case
V4L/DVB (4634): Zr36120: implement pcipci checks
V4L/DVB (4632): Zoran: Implement pcipci failure check
V4L/DVB (4631): Av7110: remove V4L2_CAP_VBI_CAPTURE flag
V4L/DVB (4630): Av7110: FW_LOADER depemdency fixed
V4L/DVB (4629): Saa7134: add card support for Proteus Pro 2309
V4L/DVB (4628): Fix VIDIOC_ENUMSTD ioctl in videodev.c
V4L/DVB (4627): Vivi crashes with mplayer
V4L/DVB (4626): On saa7111/7113, LUMA_CTRL need a different value
V4L/DVB (4624): Tvaudio: Replaced kernel_thread() with kthread_run()
V4L/DVB (4622): Copy-paste bug in videodev.c
V4L/DVB (4620): Fix AGC configuration for MOD3000P-based boards
V4L/DVB (4619): Fixes some I2C dependencies on V4L devices
V4L/DVB (4617): Problem with dibusb-mb.c USB IDs
V4L/DVB (4616): [PATCH] Nebula DigiTV USB RC support
V4L/DVB (4614): Export symbol saa7134_tvaudio_setmute from saa7134 for saa7134-alsa
...
* 'intelfb-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied/intelfb-2.6:
intelfbhw.c: intelfbhw_get_p1p2 defined but not used
intelfb: fix mtrr_reg signedness
intelfb: update doc and Kconfig (supported devices)
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add preliminary i2c support
intelfb: add vsync interrupt support
intelfb: add vsync interrupt support
intelfb: add vsync interrupt support
intelfb: add vsync interrupt support
intelfb: add vsync interrupt support
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6:
[PATCH] Use early clobber in semaphores
[PATCH] Define vsyscall cache as blob to make clearer that user space shouldn't use it
[PATCH] Re-positioning the bss segment
[PATCH] Use ARRAY_SIZE in setup.c
[PATCH] i386: replace intermediate array-size definitions with ARRAY_SIZE()
[PATCH] x86: Clean up x86 NMI sysctls
[PATCH] Refactor some duplicated code in mpparse.c
[PATCH] Document iommu=panic
[PATCH] Fix broken indentation in iommu_setup
[PATCH] Allow disabling DAC using command line options
[PATCH] Add proper sparse __user casts to __copy_to_user_inatomic
[PATCH] i386: Update defconfig
[PATCH] Update defconfig
MSI is defined to be 32-bit write. The 5706 does 64-bit MSI writes
with byte enables disabled on the unused 32-bit word. This is legal
but causes problems on the AMD 8132 which will eventually stop
responding after a while.
Without this patch, the MSI test done by the driver during open will
pass, but MSI will eventually stop working after a few MSIs are
written by the device.
AMD believes this incompatibility is unique to the 5706, and
prefers to locally disable MSI rather than globally disabling it
using pci_msi_quirk.
Update version to 1.4.45.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix some issues Steve Grubb had with the way NetLabel was using the audit
subsystem. This should make NetLabel more consistent with other kernel
generated audit messages specifying configuration changes.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patches solve the following problem: We want to grant access to devices
based on who is logged in from where, etc. This includes switching back and
forth between multiple user sessions, etc.
Using ACLs to define device access for logged-in users gives us all the
flexibility we need in order to fully solve the problem.
Device special files nowadays usually live on tmpfs, hence tmpfs ACLs.
Different distros have come up with solutions that solve the problem to
different degrees: SUSE uses a resource manager which tracks login sessions
and sets ACLs on device inodes as appropriate. RedHat uses pam_console, which
changes the primary file ownership to the logged-in user. Others use a set of
groups that users must be in in order to be granted the appropriate accesses.
The freedesktop.org project plans to implement a combination of a
console-tracker and a HAL-device-list based solution to grant access to
devices to users, and more distros will likely follow this approach.
These patches have first been posted here on 2 February 2005, and again
on 8 January 2006. We have been shipping them in SLES9 and SLES10 with
no problems reported. The previous submission is archived here:
http://lkml.org/lkml/2006/1/8/229http://lkml.org/lkml/2006/1/8/230http://lkml.org/lkml/2006/1/8/231
This patch:
Add some infrastructure for access control lists on in-memory
filesystems such as tmpfs.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I've been using systemtap for some debugging and I noticed that it can't
probe a lot of modules. Turns out it's kind of silly, the sections section
of /sys/module is limited to 32byte filenames and many of the actual
sections are a a bit longer than that.
[akpm@osdl.org: rewrite to use dymanic allocation]
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ratelimit_pages in page-writeback.c is recalculated (in set_ratelimit())
every time a CPU is hot-added/removed. But this value is not recalculated
when new pages are hot-added.
This patch fixes that problem by calling set_ratelimit() when new pages
are hot-added.
[akpm@osdl.org: cleanups]
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the list of memory nodes allowed to tasks in the top (root) nodeset
to dynamically track what cpus are online, using a call to a cpuset hook
from the memory hotplug code. Make this top cpus file read-only.
On systems that have cpusets configured in their kernel, but that aren't
actively using cpusets (for some distros, this covers the majority of
systems) all tasks end up in the top cpuset.
If that system does support memory hotplug, then these tasks cannot make
use of memory nodes that are added after system boot, because the memory
nodes are not allowed in the top cpuset. This is a surprising regression
over earlier kernels that didn't have cpusets enabled.
One key motivation for this change is to remain consistent with the
behaviour for the top_cpuset's 'cpus', which is also read-only, and which
automatically tracks the cpu_online_map.
This change also has the minor benefit that it fixes a long standing,
little noticed, minor bug in cpusets. The cpuset performance tweak to
short circuit the cpuset_zone_allowed() check on systems with just a single
cpuset (see 'number_of_cpusets', in linux/cpuset.h) meant that simply
changing the 'mems' of the top_cpuset had no affect, even though the change
(the write system call) appeared to succeed. With the following change,
that write to the 'mems' file fails -EACCES, and the 'mems' file stubbornly
refuses to be changed via user space writes. Thus no one should be mislead
into thinking they've changed the top_cpusets's 'mems' when in affect they
haven't.
In order to keep the behaviour of cpusets consistent between systems
actively making use of them and systems not using them, this patch changes
the behaviour of the 'mems' file in the top (root) cpuset, making it read
only, and making it automatically track the value of node_online_map. Thus
tasks in the top cpuset will have automatic use of hot plugged memory nodes
allowed by their cpuset.
[akpm@osdl.org: build fix]
[bunk@stusta.de: build fix]
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I am not sure about this patch, I am asking Ingo to take a decision.
task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion
it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should
live only in ->exit_state as documented in sched.h.
Note that this state is not visible to user-space, get_task_state() masks off
unsuitable states.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce the disable_irq_nosync_lockdep_irqsave() and
enable_irq_lockdep_irqrestore() APIs. These are needed for NE2000; basically
NE2000 calls disable_irq and enable_irq as locking against the IRQ handler,
but both in cases where interrupts are on and off. This means that lockdep
needs to track the old state of the virtual irq flags on disable_irq, and
restore these at enable_irq time.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It always returns 0, so relying on it is useless. The only caller isn't
checking return value. In general, un-, de-, -free functions should return
void.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently, __acquire and __release take a lock expression, but __cond_lock
takes only a condition, not the lock acquired if the expression evaluates
to true. Change __cond_lock to accept a lock expression, and change all
the callers to pass in a lock expression.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
spin_trylock_irq and spin_trylock_irqsave use _spin_trylock, which does not
use the __cond_lock wrapper annotation and thus does not affect the lock
context; change them to use spin_trylock instead, which does use
__cond_lock.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The lock annotations used on spinlocks and rwlocks currently use
__{acquires,releases}(spinlock_t) and __{acquires,releases}(rwlock_t),
respectively. This loses the information of which lock actually got
acquired or released, and assumes a different type for the parameter of
__acquires and __releases than the rest of the kernel. While the current
implementations of __acquires and __releases throw away their argument,
this will not always remain the case. Change this to use the lock
parameter instead, to preserve this information and increase consistency in
usage of __acquires and __releases.
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
